<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>自定义指令-原生demo-回顾一个DOM操作</title>
    <style>
        .demo{
            background-color: skyblue;
        }
    </style>
</head>
<body>
    <button id="btn">点我创建一个输入框</button>
    <script>
        const btn = document.getElementById('btn')
        btn.onclick = ()=>{
            const input = document.createElement('input')
             
            input.className= 'demo'
            input.value=99
            input.onclick= ()=>{alert(1)}

            document.body.appendChild(input)

            input.focus()
            input.parentElement.style.backgroundColor = 'skyblue'

            console.log(input.parentElement);
        }
    </script>
    
</body>
</html>